This invention relates to an apparatus for spectroanalysis, and more particularly to that portion of the apparatus which processes the output data of a spectrophotometer in accordance with different programs.
To obtain useful information from the output signals produced by a spectrophotometer as a result of measurement there are two data processing methods. One is to process the spectral data obtained from a single sample in the form of a curve plotted on a two-dimensional graph with the wavelength being taken along the ordinate and the magnitude of the output signal along the abscissa, while the other method is to process different data obtained from several samples measured with a fixed wavelength.
In connection with the former method there are various data processing operations for specific purposes such as to obtain difference spectra and derivative spectra, or for smoothing. The same is true with the latter data processing method. Each of these data processing operations is complete in itself in that a single or a plurality of pieces of information can be obtained by performing each data processing operation alone. The data processing operations of this characteristic will be referred to as a unit data processing operation. To take an example, for quantitative measurement of a specific component of solutes in a solvent having a curved baseline spectrum four kinds of data processing operations are required, that is, spectrum subtraction between the sample and the solvent, smoothing of the spectrum, spectrum differentiation, and calculation for quantitative determination. This type of data processing operation in which several unit data processing operations are performed successively on the original data will be referred to as a multiple data processing operation.
Conventional apparatuses for spectroanalysis are provided with individual keys each of which is intended for use for a specific unit data processing operation thereby to enable each unit data processing operation by simply depressing the corresponding specific key on the keyboard. However, to perform a multiple data processing operation comprising several unit data processing operations the same number of keys as the number of the unit data processing operations to be performed must be depressed one after another. To put it in detail, a first key is depressed to perform a first unit data processing operation on the original data, and a second key is then depressed to perform a second unit data processing operation on the processed data, and so on until the final nth key is depressed.
In the conventional apparatuses it is impossible to cause a multiple data processing operation to proceed automatically by designating at the start the sequence in which the unit data processing operations which constitute the multiple data processing operation are to be performed.
There is also known a spectrophotometer provided with a personal computer by which a desired program for the procedure of data processing can be made. However, the program for the data processing procedure must be written in a computer language such as BASIC and the work is complicated.
Accordingly, the primary object of the invention is to provide an apparatus for spectroanalysis which is capable of performing by a simple and easy operation not only individual unit data processing operations each of which is complete in itself but also a multiple data processing operation which comprises several unit data processing operations.